College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China.
Hunan Tobacco Science Institute, Changsha, 410004, China.
Environ Res. 2023 Jun 15;227:115749. doi: 10.1016/j.envres.2023.115749. Epub 2023 Mar 24.
Phytoremediation technology is an important approach applied to heavy metal remediation, and how to improve its remediation efficiency is the key. In this study, we compared the rhizospheric bacterial communities and metals contents in Miscanthus floridulus (M. floridulus) of four towns, including Huayuan Town (HY), Longtan Town (LT), Maoer Village (ME), and Minle Town (ML) around the lead-zinc mining area in Huayuan County, China. The roles of rhizospheric bacterial communities in assisting the phytoremediation of M. floridulus were explored. It was found that the compositions of the rhizospheric bacterial community of M. floridulus differed in four regions, but majority of them were heavy metal-resistant bacteria that could promote plant growth. Results of bioconcentration factors showed the enrichment of Cu, Zn, and Pb by M. floridulus in these four regions were significantly different. The Zn enrichment capacity of ML was the strongest for Cu and stronger than LT and ME for Pb. The enrichment capacity of LT and ML was stronger than HY and ME. These bacteria may influence the different heavy metals uptake of M. floridulus by altering the soil physiochemical properties (e.g., soil peroxidase, pH and moisture content). In addition, co-occurrence network analysis also showed that LT and ML had higher network stability and complexity than HY and ME. Functional prediction analysis of the rhizospheric bacterial community showed that genes related to protein synthesis (e.g., zinc-binding alcohol dehydrogenase/oxidoreductase, Dtx R family transcriptional regulators and ACC deaminase) also contributed to phytoremediation in various ways. This study provides theoretical guidance for selecting suitable microorganisms to assist in the phytoremediation of heavy metals.
植物修复技术是应用于重金属修复的重要方法，如何提高其修复效率是关键。本研究比较了中国华蓥市铅锌矿区周围的花园镇（HY）、龙潭镇（LT）、茅垭村（ME）和民乐镇（ML） 4 个镇的芒草（Miscanthus floridulus）根际细菌群落和金属含量，探讨了根际细菌群落在协助芒草植物修复中的作用。结果发现，芒草根际细菌群落的组成在四个区域存在差异，但大多数为耐重金属细菌，可促进植物生长。生物浓缩系数的结果表明，芒草在这四个区域对 Cu、Zn 和 Pb 的富集程度存在显著差异。ML 对 Zn 的富集能力最强，对 Cu 的富集能力强于 LT 和 ME，对 Pb 的富集能力强于 LT 和 ME。LT 和 ML 的富集能力强于 HY 和 ME。这些细菌可能通过改变土壤理化性质（如土壤过氧化物酶、pH 值和水分含量）来影响芒草对不同重金属的吸收。此外，共现网络分析还表明，LT 和 ML 比 HY 和 ME 具有更高的网络稳定性和复杂性。根际细菌群落的功能预测分析表明，与蛋白质合成相关的基因（如锌结合醇脱氢酶/氧化还原酶、Dtx R 家族转录调节剂和 ACC 脱氨酶）也以各种方式有助于植物修复。本研究为选择合适的微生物协助重金属植物修复提供了理论指导。
